A wide range of Fuse Fittings in the bakelite moulding and DMC moulding are available in ratings right from 20 Amps to 630 Amps. Fuse fittings from 250 A to 630A are of DMC type only. Basically two types of fuse fittings are offered:

 

1) Box type bakelite fitting (rated for 20A, 32A and 63A)
These are made of phenolic moulding material, non-inflamable, glossy, hard finish with very high insulation and a long life. Temperature rise and power loss are kept low by optimum design of contacts, which are made up of electrolytic-tinned brass with phosphor bronze backup stirrups that give the desired spring-like effect on the contacts to maintain a low resistance path. The removable front part which carries the HRC Fuse link is provided with a viewing hole to view the condition of the fuse link. 
 

These are rated for 500V AC, 50 Hz., in three sizes to suit 20A, 32A and 63A applications. A few safety components are offered as optional items, which include insulating shrouds at the bare base contacts and sleeves at the cable ends. Standard HRC Fuse links with off-set tags, similar to the NS / EI, TIA / A2, TIS / A3 can be used in these fittings. These fittings are available in types suitable for front connection, back connections and bus-bar mounting, making them ideal for all type of panel applications.

2) Open type (rated for 125A to 630A) 
These are made of bakelite for 125A and DMC for higher ratings. The inherent strength of glass reinforced polyester of DMC give these fittings a high mechanical strength while maintaining the electrical insulating properties. Silver coated copper contacts with spring steel rings ensure low power loss, minimal arc erosion and anti-corrosion properties, giving the fittings a long life in actual site conditions. These are rated for 500V AC, 50 Hz., and different sizes to suit 125A, 250A, 400A and 630A. The table shows the international size-wise break up of current ratings.